Of the races, the Tokyo gubernatorial poll is seen as a bellwether of Japan's drift to the right under Abe and his future political capital. It pits an outspoken reformer against firebrand conservative Shintaro Ishihara, the incumbent.

In some ways, Ishihara can be seen as a stand in for the prime minister.

Backed by Abe's ruling Liberal Democratic Party, Ishihara has been a champion of fiscal responsibility and conservative causes during his eight years as Tokyo governor.

But he is also a lightning rod of controversy for what critics say are disparaging remarks about foreigners and for policies seen as too nationalistic, such as the order for teachers to sing the national anthem, the "Kimigayo."

Challenger Shiro Asano, backed by the opposition Democratic Party, says Ishihara's "discriminatory comments" and "dictatorial style" are out of step with voters.

"Unless somebody stops Ishihara now, I feel that the situation not only in Tokyo but in Japanese politics as a whole may get entirely out of hand," the former governor of Miyagi prefecture said at a news conference earlier this week.

Similar criticisms might also be leveled against Abe, who has made nationalism a top rallying cry. He has pushed for teaching patriotism in the schools and reforming the pacifist constitution to give the military a bigger profile.

Deputy Cabinet Secretary Hiroshi Suzuki, an Abe spokesman, said Thursday that April's results should not be misinterpreted as a direct vote of confidence on Abe.

But the polls will nonetheless be a closely-watched barometer of the LDP's prospects in parliament's critical upper house elections in July, he said.

"Of course these elections are important," Suzuki said. "Those elections would be the run-up for the upcoming Upper House elections this coming summer."

Abe's approval rating currently hovers just above 40 percent, a drastic tumble from the 70 percent support level he enjoyed when taking office last September.

Approval has been whittled away partly by a scandal involving huge, unexplained expenses for a rent-free office linked to Agriculture Minister Toshikatsu Matsuoka.

Cabinet gaffes have also hurt. In February, Health Minister Hakuo Yanagisawa called women "birthing machines," prompting calls for his resignation.

Meanwhile, Defense Minister Fumio Kyuma ruffled feathers by declaring the U.S.-led war in Iraq, to which Japan dispatched troops, a "mistake."

Abe's troubles deepened when he angered neighboring nations by saying there was no evidence Japan's military or government forced women to work in World War II brothels.

Historians say about 200,000 women, mostly from Korea and China, served in Japanese military brothels throughout Asia in the 1930s and '40s. Many victims say they were kidnapped and forced into sexual slavery by Japanese troops.

A reinvigorated Democratic Party, led by Ichiro Ozawa, a former LDP heavyweight who defected, is waiting to pounce. And Abe's vague policy platform and nationalistic outlook may give it plenty of fodder for criticism.

The big prize will be control of parliament's upper house, up for grabs in nationwide elections this July. The April 8 polls, as well as two upper house by-elections later in the month, may foreshadow who comes out on top.